Some medical conditions can result in the degeneration of a human joint, causing a patient to consider and ultimately undergo joint replacement surgery. While joint replacement surgery is well known in the art, the decision to undergo such a procedure may be a difficult one, as the long-term success of the surgery oftentimes relies upon the skill of the surgeon and may involve a long, difficult recovery process.
The materials used in a joint replacement surgery are designed to enable the joint to move just like a normal joint. The prosthesis is generally composed of a metal piece that fits closely into and bears on a corresponding plastic component. The plastic component is typically supported on another metal piece. Several metals are typically used, including stainless steel, alloys of cobalt and chrome, and titanium, while the plastic material is typically constructed of a durable and wear resistant polyethylene. Plastic bone cement may be used to anchor the prosthesis into the bone, however, the prosthesis may be implanted without cement when the prosthesis and the bone are designed to fit and lock together directly.
To undergo the operation, the patient is given an anesthetic while the surgeon replaces the damaged parts of the joint. For example, in knee replacement surgery, the damaged ends of the bones (i.e., the femur and the tibia) and the cartilage are replaced with metal and plastic surfaces that are shaped to restore knee movement and function. In another example, to replace a hip joint, the damaged ball (the upper end of the femur) is replaced by a metal ball attached to a metal stem fitted into the femur, and a plastic socket is implanted into the pelvis, replacing the damaged socket. Although hip and knee replacements are the most common, joint replacement can be performed on other joints, including the ankle, foot, shoulder, elbow and fingers.
As with all major surgical procedures, complications can occur. Some of the most common complications are typically thrombophlebitis, infection, stiffness, and loosening. While thrombophlebitis (i.e., vein inflammation related to a blood clot) and infection are oftentimes treated medically, stiffness and loosening may require additional surgeries. One technique utilized to reduce the likelihood of stiffness and loosening relies upon the skill of the surgeon to align and balance the replacement joint along with ligaments and soft tissue during surgery.